For endangered foxes, traps are a healthy thing

Graphics

Catching the cat-size island fox is a simple proposition: a little cat food, it turns out, and a pungent lure.

Biologists working their trap lines on Santa Catalina Island routinely recapture the same animals as they move along the island's spine, monitoring, vaccinating and caring for what is likely one of the best-protected endangered species in the world.

“They're considered a trap-happy species, because they get this positive reinforcement,” Julie King, director of wildlife management at the Catalina Island Conservancy, said recently as she checked one of dozens of traps hidden in the island's brush. “They tend to be very easy to capture over and over.”

The tiny foxes, nearly wiped out in 1999 by an outbreak of canine distemper, have made what their caretakers consider to be an astonishing comeback. From a low of about 100 animals, they now number an estimated 1,500 – a figure that might be close to the maximum fox population the island can sustain.

“This is one of the fastest recoveries of an endangered species on record,” said conservancy President and CEO Ann Muscat.

But threats to the foxes remain; conservancy scientists must keep close tabs on them, drawing blood from captives to check for distemper and rabies, and placing radio collars on “sentinel” foxes that remain unvaccinated so they can pick up whatever diseases might be lurking and alert biologists.

The foxes, one of six subspecies found among the eight Channel Islands off California, have likely inhabited Catalina for thousands of years – as long as 8,000 by a recent estimate, and perhaps as long as 10,000, said conservation manager John Mack.

Whether they arrived on a raft of vegetation flushed into the sea by storm or were carried to the island by early Native Americans, the foxes have become a kind of rock-star species among the island's natives.

Today, however, they must share the island with many non-native imports – not only with bison, descended from a herd brought to Catalina for a movie in which they never appeared, but the island's human residents, their pets and interlopers like raccoons, the original source of the distemper outbreak.

So every year, King and other conservancy biologists make their six-week trapping runs, using a battery of tools to give the animals shots and checkups.

Keeping them calm requires no sedation, as it does with the capture of larger animals on the mainland.

All the foxes need is a combination muzzle and mask that covers their eyes while the scientists keep a firm hold on them for 10 to 15 minutes as they do their work.

“I have two gloves and a decoy glove,” King said as she drew a male roughly 4 years old from a cage trap he might have been inside overnight. “This saves my fingers.”

But the fox, which had been trapped before, only growled a bit, then remained quiet and cooperative once he was comfortably situated in King's lap.

The fox had been weighed while still in the cage (the cage's weight is subtracted later). King rolled him on his back to check his eyes – all clear – and his teeth. This one had a few missing, normal for his age, as well as significant tooth wear.

He was plump with cactus fruit, King noted; the mask was fitted into place and his limbs were checked for injuries.

“They fight with each other for territory and mating,” King said. “Oftentimes, the males have some pretty serious bite wounds on their ankles, back feet and tails.”

Then came the most sensitive part of the operation: drawing a blood sample from either the fox's carotid artery or jugular vein.

Visitors watching were asked not to shuffle their feet during the blood draw.

“The gravel, people walking; it makes them feel like something's sneaking up on them,” King had explained earlier.

After that came two vaccinations, rabies in the right leg and distemper in the left, and a quick comb to check for fleas, lice and ticks.

Finally she peered into the fox's ears with a special scope to look for ear mites, as well as signs of ear cancer, a disease known to afflict fox populations in the southern Channel Islands.

Age-related disease is a consequence of the foxes' long lifespan in the absence of predators.

“A gray fox on the mainland, their average lifespan is one to three years,” King explained later. “Here, these guys live 10 to 12 years, and they start developing a lot of issues that are very characteristic of geriatric dogs – things like arthritis and cancer.”

This fox, however, received a clean bill of health. A quick removal with forceps of a bit of grass seed deep in one ear – by coincidence, a type known as “fox tail” – then a few drops of ear-mite treatment, and King removed the mask and pointed the fox at the roadside.

Once released, he sprang over the road bank and down a slope, disappearing into the brush.

King then outfitted the trap for its next captive.

She replaced the grass in the bottom, loaded it with both dry and wet cat food in case of a long wait in the trap, and added the lure, called loganberry, with a powerful, fruity aroma the foxes apparently find irresistible.

“He spent a lot of time chewing on the bait can, so it looks like a shotgun hit it,” King said. “So I will replace that with a nice, new one.”

User Agreement

Keep it civil and stay on topic. No profanity, vulgarity, racial
slurs or personal attacks. People who harass others or joke about
tragedies will be blocked. By posting your comment, you agree to
allow Orange County Register Communications, Inc. the right to
republish your name and comment in additional Register publications
without any notification or payment.